Iowa 

Agricultural  Collage, 
Department  of  Entomology, 

•>  in  Iowa. 
88) 


5fi7 


AGRICULTURAL 
LIBRARY, 

UNIVERSITY 

— *OF*— 

CALIFORNIA. 


BULLETIN 


-OF    THE- 


IOWA  AGRICULTURAL  COLLEGE 


FROM    THE- 


DEPARTMENT  OF  ENTOMOLOGY, 


BY  HERBERT  OSBORN, 


ISSUED  JANUARY,  1888, 


cso7 


THE  CHINCH  BUG  IN   IOWA. 

The  extensive  ravages  of  the  Chinch  Bug  (Blissus  kucoptems.  Say) 
during  the  past  season,  which  have  had  no  precedent  in  the  history  of  the 
State,  together  with  the  present  strong  probability,  that  it  will  be  equally 
destructive,  perhaps  more  so,  the  present  year,  make  it  important  that  the 
fullest  knowledge  of  its  habits  and  the  best  known  methods  of  preventing 
its  damages,  should  be  thoroughly  distributed  throughout  the  State. 

According  to  the  Iowa  Crop  Report,  issued  July  16th,  including  reports 
from  correspondents  up  to  July  10th,  this  insect  had  already  become  notice- 
able in  three-fourths  of  the  counties  of  the  State  arid  its  damage  to  the 
wheat  crop  had  run  into  the  millions  of  dollars.  Availing  myself  of  the 
kind  offer  of  Secretary  Shaffer,  of  the  State  Agricultural  Society,  to  co-op- 
erate in  getting  statistics  of  damage  in  the  State,  I  prepared  a  set  ot  ques- 
tions which  he  included  in  his  blanks  sent  to  correspondents,  at  the  same 
time  including  a  brief  note  on  work  that  might  profitably  be  done  in  Fall. 
The  full  result  of  the  returns  from  these  queries  are  not  yet  available,  but 
will  be  published  shortly  in  the  final  Crop  Report  of  the  season.  Mr. 
Shaffer  has  however  kindly  favored  me  with  estimates  from  the  reports 
already  examined,  from  wrhich  it  appears  that  the  damage  to  the  crops, 
wheat,  oats,  barley  and  corn,  will  approximate  twenty-five  millions  of 
dollars  at  least.  An  item  by  no  means  insignificant  even  when  distributed 
among  all  the  farmers  of  the  State. 

In  the  present  Bulletin  I  shall  not  attempt  an  elaborate  discussion  of 
the  Chinch  Bug  or  of  the  methods  of  attacking  it,  but  endeavor  to  give  in 
brief  space  the  facts  of  economic  importance  with  recommendations  for 
remedies  that  should  be  universally  known. 

The  portion  summarizing  life  history  and  habits,  and  the  synopsis  of 
remedies,  have  been  published  in  the  College  Biennial  Report  for  the  years 
1886  and  1887,  pp.  60-67. 

The  observations  and  experiments  with  remedies  were  carried  on  as 
agent  of  the  Division  of  Entomology,  U.  S.  Department  of  Agriculture,  at 
the  instance  of  the  Entomologist,  Professor  C.  V.  Riley.  Detailed  reports 
have  been  forwarded  to  him  and  he  has  very  kindly  granted  permission  to 
include  such  portions  as  have  more  immediate  importance  in  this  Bulletin. 

Professor  Riley  will  include  in  his  forthcoming  report  to  the  Commis- 
sioner of  Agriculture,  an  extended  article  on  the  Chinch  Bag,  with  detailed 
discussion  of  its  habits,  remedies,  etc.  He  informs  me  that  this  report  will 
be  issued  early  in  Spring,  and  I  would  strongly  recommend  all  farmers  of 
the  State  to  make  early  application  to  their  respective  members  of  Congress 
for  copies  of  the  report,  and  to  carefully  study  the  portion  relating  to  the 
Chinch  Bug. 

LIFE-HISTORY  AND  HAHIT.s. 

The  life-history  and  habits  of  the  species  have  been  very  fully  recorded, 
it  having  been  studied  in  detail  by  such  entomologists  as  Fitch,  Riley, 
Walsh,  LeBaron,  Shimer,  Thomas,  Forbes  and  others.  The  facts  here 
stated  must  not  therefore  be  looked  upon  as  given  with  any  claim  of  origin- 


4  IOWA  AGRICULTURAL  COLLEGE. 

ality,  though  I  have,  I  think,  verified  by  personal  observation  nearly  every 
statement  here  recorded. 

At  the  present  time  (Winter)  Chinch  Bugs  are  in  the  adult  stage,  and 
may  be  found  secreted  under  grass,  dead  leaves,  rubbish  of  various  kinds, 
both  in  the  fields  and  in  thickets  or  timber,  especially  along  borders  of 
thickets  or  wood,  under  leaves,  loose  bark,  etc.  In  the  Spring  these  adults 
issue  and  after  finding  suitable  plants  for  the  food  of  the  young  deposit 
their  eggs.  The  eggs  are  about  one-thirty-second  of  an  inch  in  length, 
rather  slender,  slightly  curved,  of  a  yellow  color  and  one  end  (the  head  end) 
is  truncated  or  apparently  cut  square  across,  and  on  this  end  are  four  small 
granules  or  tubercles,  too  small  to  be  seen  with  the  naked  eye.  The  egg 
becomes  darker  as  it  nears  the  time  for  hatching,  and  at  the  head  end  the 
eyes  may  be  seen  plainly  through  the  egg  walls.  Each  female  is  said  to  be 
capable  of  laying  about  five  hundred  eggs,  occupying  about  twenty  days  in 
their  deposition,  so  that  if  wet  weather  destroys  those  deposited  at  one  time, 
others  are  likely  to  escape.  The  process  begins  in  April  (possibly  earlier  in 
favorable  seasons)  and  extends  into  May.  If  wheat  is  available  this  will 
be  the  principal  crop  attacked  at  this  time,  but  eggs  may  also  be  laid  in 
oats,  rye,  barley,  corn  and  various  grasses.  The  bugs  depositing  eggs  live 
for  some  time  afterward;  if  plenty,  may  even  do  some  damage  to  the  crop, 
but  usually  they  are  too  few  in  number  to  cause  trouble,  and  they  gradually 
die  off  till  by  the  time  their  offspring  mature  they  are  mostly  dead. 

The  eggs  hatch  into  minute  yellow  or  light  red  bugs,  which  have  the 
same  general  form  as  the  adults.  They  begin  feeding  on  the  roots  of  the 
plant  where  the  eggs  were  laid.  (Eggs,  it  is  said,  may  be  laid  above  ground, 
but  they  are  almost  always  found  on  the  stems  or  roots  of  the  plant,  half 
an  inch  or  more  beneath  the  surface.)  After  growing  for  a  time  the  larva 
sheds  its  skin,  assuming  a  darker  color,  but  retains  a  light  band  across  the 
middle  of  the  back.  After  growing  for  another  period  it  moults  again, 
assuming  after  this  moult  a  brownish  color  with  a  whitish  line  across  the 
back.  After  still  another  moult  it  becomes  nearly  black  save  the  white 
band  on  the  back,  and  in  this  stage  the  wing  pads  become  well  developed, 
indicating  the  pupa  stage,  and  when  another  moult  occurs  (really  the  trans- 
formation from  pupa  to  adult,)  the  insect  assumes  the  winged  condition. 
It  is  now  three-sixteenths  of  an  inch  long,  of  a  deep  black  color  and  with 
white  wings,  which  have  a  black  spot  on  the  border  near  the  middle.  Bugs 
which  have  hatched  in  April  or  May  become  mature  in  the  latter  part  of 
June  or  in  July,  and,  after  pairing,  another  lot  of  eggs  is  deposited  to 
produce  a  second  brood  of  bugs.  The  bugs  which  have  been  feeding  in 
wheat,  however,  find  upon  its  ripening  that  they  must  migrate  or  starve,  so 
that  there  is  a  general  movement  of  bugs,  both  mature  and  partially  devel- 
oped, from  wheat  fields  into  corn,  etc.,  accomplished  as  a  rule  on  foot  by  the 
winged  bugs  as  well  as  the  immature  ones.  Sometimes  in  July  there  is  a 
general  flight  of  bugs,  and  at  such  times  the  air  will  be  loaded  with  bugs, 
and  fields  which  have  not  been  previously  infested  will  swarm  with  them. 
This  is  bad  enough,  but  as  each  female  of  this  swarm  deposits  hundreds  of 
eggs,  it  is  riot  long  till  the  field  is  so  packed  with  bugs  that  the  plants 
rapidly  succumb.  On  corn  they  will  cluster  on  the  stalks  from  the  roots  to 
near  the  tops  of  the  leaves,  while  on  grasses  such  as  Hungarian,  fox-tail, 
etc.,  every  part  of  the  plant  may  be  crowded  with  them.  The  second  brood 
attains  its  growth  during  the  late  Summer  and  Fall,  and  by  the  time  cold 
weather  approaches  nearly  all  have  reached  the  mature  form  and  »re  ready 
to  secrete  themselves  for  the  Winter. 


THE  CHINCH  BUG  IN  IOWA.  5 

OBSERVATIONS  AT  AMES. 

Chinch  Bugs  were  observed  in  the  Fall  of  1886  but  not  in  such 
numbers  as  to  cause  serious  apprehension.  Had  the  Spring  of  1887 
been  an  ordinary  one  I  scarcely  think  the  bugs  would  have  been  very 
noticeable  here.  They  were  not  noted  as  particularly  abundant  early 
in  the  Spring,  but,  by  the  latter  part  of  June,  they  were  causing  some 
damage  in  a  small  patch  of  experimental  wheat  on  the  College  Farm. 

By  the  middle  of  July  they  were  accumulating  on  corn  adjoining 
the  small  patch  of  wheat  that  had  then  been  cut,  though  hosts  of 
them  could  still  be  seen  traveling  in  the  stubble.  They  were  also 
abundant  in  a  field  of  Hungarian  grass,  which,  at  this  time,  had  made 
a  growth  of  about  six  inches,  also,  in  smaller  numbers,  scattered 
through  fields  of  sod  corn.  These  last  I  think  it  not  unlikely  had 
developed  from  eggs  laid  in  the  grass,  as  the  sod  was  not  turned  till 
late.  The  majority  of  the  bugs  at  this  time  (July  14th  and  15th) 
were  in  the  pupa  and  imago  stages  though  larvae  were  not  scarce. 
Numbers  of  the  adults  were  seen  pairing  at  this  time.  On  the  16th 
bugs  were  still  plenty  in  the  stubble  and  the  stubble  was  fired  {see 
experiments  with  remedies.)  Adults  were  seen  taking  wing  from 
the  tops  of  corn  stalks  and  other  elevated  positions.  July  "l  9th  I 
found  Chinch  Bug  eggs  quite  plenty  in  ground  at  base  of  corn 
stalks,  between  sheath  of  leaf  and  stalk  and,  in  some  cases,  among 
the  cast  off  skins  of  the  bugs  under  lumps  of  earth.  Some  of  these 
eggs  were  nearly  ready  to  hatch,  others  apparently  but  recently  laid. 
On  the  20th  both  Chinch  Bugs  and  their  eggs  were  noted  in  sod 
corn.  On  July  25th  Chinch  Bugs  were  swarming  in  the  air,  at  times 
passing  rny  window  in  immense  numbers.  They  appeared  to  be 
much  thicker  at  times,  at  short  periods,  few,  if  any*,  being  observed. 
They  were  first  noticed  shortly  after  one  o'clock  p.  in.  I  saw  no 
evidence  of  pairing  as  a  result  of  flight.  The  bugs  were  mostly 
flying  from  southeast  to  northwest,  the  direction  of  the  wind  at  the 
time.  On  July  27th  Chinch  Bugs  were  again  noticed  on  the  wing, 
but  not  in  such  great  numbers  as  on  the  25th.  Flying  from  north- 
west to  southeast,  with  the  wind.  On  August  3rd  newlv  hatched 
bugs  were  plenty  on  some  hills  of  corn  scattered  through  the  field 
but  the  damage  from  them  was  not  yet  very  marked.  They  could  be 
found  in  greatest  numbers  on  the  roots  and  base  of  the  stems  of  fox- 
tail grass.  A  field  of  Hungarian  grass,  late  planted  on  sod,  and 
having  about  two  weeks  growth,  contained  adult  bugs  in  great 
numbers,  many  of  them  pairing,  others  laying  eggs,  and  the  air 
above  the  field  contained  hosts  of  them  on  the  wing.  It  was  evident 
that  the  field  would  suffer  severely  as  soon  as  the  eggs  from  the 
immense  number  of  bugs  congregated  here  should  hatch.  Both  corn 
and  grass  showed  effects  of  drouth  at  this  time  in  curled  and  wilted 
loaves,  this  effect  being  seen  in  places  where  bugs  were  not  yet 
abundant  as  well  as  where  they  were  thick.  The  early  planted  Hun- 
garian grass  showed  many  spots  wilted  while  young  bugs  were 
abundant  on  the  roots  and  on  stems  at  surface  of  the  ground. 

On  August  12th  bugs  in  corn  were  becoming  fairly  plenty  in 
places  and  some  parts  showing  damage.  In  the  young  Hungarian, 
on  sod,  the  newly  hatched  bugs  were  very  plenty  and  the  grass  suf- 
fering severely.  A  few  adults  were  observed  pairing  but  by  no  means 


C  IOWA  AGRICULTURAL  COLLEGE. 

so  plenty  as  a  week  or  ten  days  previously.  The  older  Hungarian 
was  full  of  young  bugs,  many  newly  hatched.  A  portion  of  the  field 
was  cut  a  week  before  this  but  bugs  were  plenty  in  the  stubble. 
Some  of  the  grass  still  standing  was  nearly  dry  enough  to  burn. 

On  August  13th  the  Chinch  Bugs  in  the  older  Hungarian  com- 
menced to  travel  to  the  adjacent  corn,  the  greater  number  of  the 
migrants  being  in  the  black  larval  and  pupa  states,  though  many 
were  younger  and  some  adult.  The  grass  would  burn  in  places  and 
in  such  places  great  numbers  of  bugs  could  be  killed,  but  in  most 
places  there  was  too  much  green  grass  for  it  to  burn  readily.  Fur- 
rows detained  many,  and  great  numbers,  particularly  of  the  younger 
ones,  died  in  and  at  sides  of  the  furrows.  Some  of  the  adult  bugs 
pairing  at  this  time.  On  the  16th  and  for  one  or  two  days  thereafter, 
which  were  cool  and  cloudy,  there  was  not  much  migration,  and 
while  it  continued  to  some  extent  for  a  number  of  days,  at  no  time 
did  they  travel  so  rapidly  as  on  the  13th  to  15th.  From  this  time  on 
the  bugs  were  at  work  in  corn  and  Hungarian,  but  the  corn  was  cut 
as  early  as  possible  to  avoid  loss,  and  much  of  the  younger  Hungar- 
ian was  entirely  destroyed  so  they  were  forced  to  scatter.  As  late  as 
November  15th  however  a  few  adult  bugs  were  to  be  found  in  these 
fields  running  over  the  surface  of  the  ground  or  concealed  under 
sods,  tufts  of  grass,  etc.  A  number  were  found  secreted  in  a  cabbage 
head  between  the  outer  leaves  during  the  early  part  of  December. 
There  is  every  reason  to  believe  that  immense  numbers  of  them 
have  gone  into  Winter  quarters  in  best  of  condition  and  that  so  far 
as  the  condition  of  bugs  is  concerned  they  may  prove  far  worse  the 
coming  season  than  the  season  that  has  passed. 

REMEDIES  TRIED  AT  AMES. 

KEROSENE  EMULSION. — A  number  of  tests  of  this  remedy  were 
made,  first  with  a  view  to  testing  its  value  under  various  conditions, 
and  afterward  for  the  sake  of  checking  the  damage  threatened  to 
corn  in  some  fields  on  the  College  Farm. 

The  first  trial  was  made  July  15th,  the  emulsion  used  being  the 
common  one  consisting  of  kerosene,  soap  and  water  diluted  to  about 
five  per  cent  kerosene.  The  bugs  were  killed  very  quickly  by  this- 
application,  and  great  numbers  of  them  could  be  reached  but  many 
in  particularly  secreted  places,  in  folds  of  leaves  and  under  lumps  of 
earth  escaped.  Thrown  upon  the  leaves  and  running  down  between 
leaf  and  stalk,  it  dislodged  and  killed  immense  numbers.  Thrown 
against  stalks  where  they  were  congregated  it  would  quickly  dislodge 
the  mass,  and  while  it  was  impossible  to  see  whether  all  driven  off 
in  this  way  were  sufficiently  wet  to  kill  them  it  was  certain  that  most 
of  them  wrere.  This  application  was  at  the  rate  of  about  one  gallon 
of  emulsion  or  twelve  gallons  of  the  diluted  mixture  to  five  rows  of 
corn,  for  thirty-two  rods  or  what  would  equal  five  gallons  of 
emulsion,  sixty  gallons  of  diluted  mixture,  to  the  acre,  or  a  cost  for 
material  of  less  than  sixty  cents  per  acre.  In  trials  of  emulsion 
diluted  to  range  from  two  per  cent,  to  seven  per  cent,  of  kerosene, 
less  than  four  or  five  per  cent,  was  found  unsatisfactory,  and  at  the 
lowest  figure  bugs  even  when  thoroughly  drenched,  and  kept  for  a 
timo  in  the  fluid  were  able  to  recover.  A  mixture  (about  two  per 


THE  CHINCH  BUG  IX  IOWA.  7 

cent,  possibly  a  little  less)  which  killed  plant  lice  almost  instantly, 
affected  Chinch  Bugs  but  slightly  if  at  all,  and  they  afterward  recov- 
ered and  lived  in  confinement  for  many  days. 

On  August  15th  applied  kerosene  emulsion  to  bugs  accumulating 
on  corn  rows,  using  an  emulsion  diluted  to  contain  about  six  per 
cent,  kerosene  and  spraying  with  cyclone  nozzle  from  a  wagon;  great 
numbers  could  be  found  dead  within  a  few  minutes  after  the  applica- 
tion, and  on  the  following  day  hosts  of  dead  could  be  found  on  the 
ground  around  the  hills  treated.  In  places  however  the  stalks  had 
become  well  covered  by  live  bugs  that  had  moved  in  to  fill  the  places 
of  those  destroyed.  As  this  application  was  made  irregularly  on 
hills  most  infested  on  an  irregular  patch  I  cannot  say  as  to  the  exact 
amount  used  on  a  given  area,  but  think  it  was  less  than  used  in 
previous  applications. 

Subsequently  the  Farm  Department  applied  on  a  large  scale 
using  a  five  to  six  per  cent,  emulsion,  and  spraying  from  barrels  in  a 
wagon,  one  man  working  the  force  pump  and  managing  the  team, 
while  another  manipulated  the  hose  and  nozzle,  walking  rapidly 
among  the  hills  of  corn  and  directing  the  spray  upon  masses  of  bugs. 
This  resulted  in  the  destruction  of  great  numbers  of  bugs,  but  no 
record  of  the  area  being  kept,  it  is  impossible  to  state  the  exact  cost. 

The  cyclone  nozzle  was  found  by  all  means  the  most  satisfactory 
in  spraying  for  this  purpose. 

I  suggested  the  trial  of  emulsion  to  some  of  my  correspondents, 
and  I  extract  a  paragraph  from  one  letter  received  in  reply. 

DEAR  SIR:  Your  most  satisfactory  letter  received  some  time 
since.  The  emulsion  is  a  success;  it  was  instant  death  to  the  Chinch 
Bugs,  but  it  takes  so  much  when  you  want  to  go  over  five  or  six 
acres  that  one  cannot  stand  the  expense.  It  could  be  stood  to  go 
over  it  once  or  twice  if  I  could  have  got  the  bugs  all  on  the  corn, 
but  they  would  a  part  stay  on  the  corn  while  the  rest  would  lie  under 
sods  and  anything  else  that  would  protect  them  from  the  sun. 

J.  E.  WARREN,  Cambridge,  Iowa. 

The  use  of  kerosene  can  hardly  be  expected  to  prove  of  value 
except  when  the  bugs  are  massing  on  corn;  at  this  time  application 
to  an  acre  or  two  of  the  field  next  to  stubble  may  do  much  to  save 
the  rest  of  the  field.  By  arranging  nozzles  with  special  reference  to 
most  efficient  work  in  corn  rows  and  while  corn  is  small  enough  to 
drive  a  team  astride  of  one  row  I  think  spraying  can  be  done 
thoroughly  at  a  cost  of  thirty  to  forty  cents  per  acre  for  material.  A 
cyclone  nozzle  with  pressure  sufficient  to  do  good  work,  discharges 
about  one  pint  of  liquid  per  minute.  Adjusting  three  nozzles  to  play 
upon  one  row  of  corn,  one  each  side  and  one  from  above,  and 
allowing  the  team  to  walk  slowly  (two  miles  per  hour)  it  will  take 
thirty  gallons  of  liquid  per  acre,  which,  using  five  or  six  per  cent, 
emulsion,  costs  about  thirty  cents,  exclusive  of  labor,  which  for  team 
and  man  an  hour  and  a  quarter  would  be  about  forty  cents  more. 
First  cost  of  force  pump  must  of  course  be  considered.  The  cost  of 
labor  on  the  farm  however  where  the  farmer  uses  his  own  team  and 
does  the  managing  of  the  apparatus  himself  might  be  considered 


8  IOWA  AGRICULTURAL  COLLEGE. 

less.  By  using  only  two  nozzles,  or  by  driving  faster  than  the  above 
estimate  allows,  the  expense  would  be  lessened.  It  might  do  in 
applying  in  this  manner  to  reduce  the  emulsion  to  four  per  cent.,  but 
beyond  this  I  do  not  think  it  will  do  to  go  with  any  expectation  of 
getting  satisfactory  results. 

BURNING  STUBBLE  AND  GRASS. — On  July  16th  the  stubble  adjoin- 
ing a  corn  field  was  observed  to  contain  large  numbers  of  bugs 
traveling  toward  corn.  In  the  afternoon  this  migration  was  going  on 
quite  rapidly,  and  as  the  stubble  was  now  quite  dry  it  was  fired  with  a 
view  to  destroying  the  bugs  remaining.  Where  tolerable  thick  and 
when  there  was  a  fair  breeze  it  burned  quite  readily,  but  it  was 
necessary  to  take  some  pains  in  carrying  the  flame  along  past  thin 
spots  to  keep  it  from  dying  out.  A  considerable  portion  of  the  field 
however  was  successfully  burned  over,  and  the  dead  bodies  of  many 
bugs  not  entirely  consumed,  which  could  be  readily  found  on  exam- 
ination of  the  burnt  area,  testified  to  the  destruction  of  hosts  of  the 
pests.  The  bugs  thus  destroyed  were  mostly  young  larvae,  the 
majority  of  the  adults,  pupae  and  larger  larvae  having  moved  out. 
The  number  destroyed  must,  I  believe,  have  well  repaid  the  little 
trouble  necessary  to  burn  the  stubble. 

Early  in  August  the  bugs  had  so  multiplied  in  a  field  of  Hun- 
garian grass  that  no  further  growth  seemed  probable,  and  most  of 
the  field  was  mown  and  the  hay  secured.  A  narrow  strip  was  left 
next  the  corn  adjoining  the  field,  the  plan  being  to  burn  this  as  soon 
as  bugs  began  passing  from  the  grass  to  corn.  When  the  bugs 
started,  however,  (August  13th)  the  grass  was  not  dry  enough  to  burn 
except  in  spots.  In  such  places  as  would  burn,  however,  hosts  of 
bugs  were  consumed.  This  strip  was  at  once  mown,  and  after  drying 
a  few  hours  another  attempt  made  to  burn  it,  as  also  on  the  following 
day,  but  portions  were  still  too  green  to  burn  rapidly,  and  unfortun- 
ately for  the  experiment  the  two  or  three  days  following  were  not  hot 
and  dry  enough  to  render  it  fit  to  burn  readily.  A  few  days  later, 
however,  on  a  dry  day  with  a  fair  breeze,  most  of  the  strip  remaining 
unburnt  was  burned  over,  and  examination  showed  that  great  numbers 
of  young  bugs,  even  at  this  late  day,  were  consumed.  Bugs  if 
underground,  or  secreted  in  roots  of  stubble,  will  not  be  heated 
enough  to  kill  them,  hence  to  destroy  the  greatest  number  as  well  as 
to  secure  the  most  rapid  burning,  the  fire  should  be  started  in  the 
hottest  part  of  the  day  when  bugs  in  greatest  number  will  be 
moving. 

OBSTRUCTING  MIGRATION. — The  common  method  of  checking 
migration  by  making  furrows  often  proves  unsatisfactory,  and  several 
tests  were  made  to  ascertain  the  conditions  securing  the  most  perfect 
check.  It  was  found  that  a  single  mark,  two  or  three  inches  deep, 
the  sides  of  which  were  composed  of  fine  dust,  would  form  a  com- 
plete barrier  to  their  progress;  the  bugs  accumulating  in  the  furrows 
being  utterly  unable  to  crawl  up  the  dusty  sides.  Any  solid  place, 
however,  which  would  give  them  a  foothold,  would  permit  them  to 
pass. 

A  couple  of  furrows  were  plowed  between  grass  and  corn,  and 
pulverized  by  drawing  a  log  along  them,  and  the  result  watched.  In 


THE  CHINCH  BUG  IN  IOWA.  o 

a  very  short  time  immense  numbers  were  struggling  to  escape  from 
the  furrows  and  taking  advantage  of  every  object  that  would  furnish 
them  a  foothold  upon  which  to  pass.  Many  of  them  would  accumu- 
late at  the  side  of  the  furrow  next  the  grass,  not  even  entering  the 
furrow.  Subsequently  many  were  found  dead  along  the  furrows, 
some  within, and  others  simply  at  the  edge  next  the  grass.  Knowing 
that  the  cast  off  skins  of  the  larvae  closely  resemble  dead  bugs,  I 
examined  a  number  of  handfuls  in  order  to  be  sure  that  they  were 
dead  bugs  and  not  merely  the  cast  off  skins  of  those  that  had 
moulted.  Whether  they  died  from  starvation  or  because  they  could 
not  secure  the  protection  which  they  endeavor  to  obtain  at  night,  I 
do  not  pretend  to  say,  though  the  former  seems  the  more  likely,  since 
many  secreted  themselves  under  weeds,  straw  and  even  in  the  earth, 
to  which  all  had  access.  Some  bugs  collected  along  the  furrows 
were  destroyed  by  drawing  heavy  straw  torches  along  over  the 
thickest  masses.  As  the  corn  in  this  case  was  pretty  well  grown,  the 
farm  management  preferred  to  cut  and  shock  it  for  fodder  rather 
than  keep  the  furrows  in  order,  and  in  a  short  time  they  ceased  to  be 
any  obstruction.  The  main  difficulty  with  furrows  as  usually  made, 
is  that  they  present  at  many  points  solid  walls,  pieces  of  sod,  large 
clods,  tufts  of  grass,  etc.,  which  serve  as  highways  for  the  migrating 
host.  I  believe  that  the  most  effectual  check  will  be  made  by  draw- 
ing a  triangular  block  or  weighted  trough  along  a  dry  furrow  or 
between  rows  of  corn  simply  over  the  surface  of  the  loose  earth. 
The  trough  could  be  made  by  nailing  together  two  pieces  of  plank 
four  to  six  feet  long,  fastening  a  hook  at  one  end  to  hitch  a  chain  to, 
and  weighting  by  putting  in  stones  to  which  may  be  added  the 
weight  of  the  driver.  When  used  between  corn  rows  to  prevent 
advance  of  bugs  already  in  the  field,  it  could  be  kept  in  position  by 
side  pieces,  which  could  also  be  arranged  to  make  shallow  marks,  thus 
forming  three  parallel  furrows  at  once.  To  prevent  the  bugs  passing 
from  wheat  stubble  to  corn,  furrows  should  be  plowed  some  days 
before  migration  begins,  and  the  ground  turned  two  or  three  times  or 
till  well  pulverized,  then,  as  soon  as  bugs  show  any  signs  of  travel- 
ing, the  trough  should  be  drawn  along  the  furrow  to  reduce  the  sides 
to  dust,  and  this  process  should  be  repeated  every  dry  and  hot  day, 
by  ten  o'clock  in  the  forenoon,  so  long  as  bugs  attempt  to  pass.  The 
bugs  accumulated  in  the  furrow  will  thus  many  of  them  be  crushed 
and  the  sides  of  the  furrow  kept  finely  pulverized. 

Experiments  were  also  made  with  Pyrethrum  and  Bisulphide  of 
Carbon,  the  former  proving  entirely  unsatisfactory,  while  the  latter, 
though  promising  to  be  of  some  value  under  certain  conditions,  will 
need  to  be  given  further  trial  before  a  definite  opinion  as  to  its  value 
can  be  formed. 

While  it  is  very  desirable  to  find  some  cheap  and  efficient 
method  of  destroying  the  bugs  when  present  and  destroying  any 
particular  crop,  the  greatest  reliance  will  probably  always  have  to  be 
placed  upon  preventive  measures,  and  the  success  of  these  will 
depend  upon  the  promptitude  and  energy  with  which  they  are 
adopted  by  the  farmers  of  every  community  in  the  State  where  bugs 
are  now  present. 

The  best  known  methods  are  summarized  below. 


10  IOWA  AGRICULTURAL  COLLEGE. 

REMEDIAL,  AND  PREVENTIVE  MEASURES. 

Professor  Forbes,  State  Entomologist  of  Illinois,  in  a  recent  Bulletin 
makes  the  following  pertinent  remarks  concerning  the  general  neglect  of 
applying  remedies  for  this  pest: 

"There  is  a  general  but  mischievous  impression  among  the  farmers  of 
this  State,  especially  to  the  southward,  that  it  is  useless  to  contend  against 
the  Chinch  Bug,  and  that  its  visitations  must  be  received,  like  those  of  the 
drought  and  the  tornado,  as  evils  beyond  our  power  to  prevent  or  remedy, 
A  careful  study  of  the  literature  of  the  subject,  several  years'  observation 
in  the  field,  and  some  experiments,  have  convinced  me  that  this  belief 
often  doubles,  at  least,  the  calamity  of  the  outbreak,  by  discouraging  at 
the  outset  any  except  sporadic  and  individual  measures  of  defense.  This 
discouragement  is,  of  course,  not  without  its  reasons.  Commonest,  I 
think,  are  the  following: 

ul.  In  this,  as  in  many  other  cases  of  insect  injury,  the  number  of 
unreasonable  and  even  preposterous  recommendations  that  have  been 
made  have  tended  to  discredit  the  whole  subject  of  remedial  measures. 

"2.  Few  are  aware  of  the  very  considerable  number  of  valuable  reme- 
dies which  have  been  carefully  tried,  here  and  there,  with  decisive  or  highly 
encouraging  results. 

"3.  Failures  of  measures  not  intelligently  or  thoroughly  applied,  or 
applied  under  exceptional  circumstances,  have  often  led  to  the  conclusion 
that  there  was  no  value  in  them  under  any  circumstances  whatever. 

"4.  Partial  or  complete  failure  of  the  isolated  efforts  of  individuals  has 
sometimes  illegitimately  discouraged  combined  action  by  the  farmers  of  a 
neighborhood. 

"5.  The  use  of  proper  measures  in  the  beginning  of  an  outbreak  has 
been  prevented  by  the  failure,  elsewhere  or  previously,  of  the  same 
measures  when  the  Chinch  Bug  had  already  overwhelmed  the  country. 
The  best  of  remedies  will  fail  when  the  patient  is  already  in  the  article  of 
death. 

"6.  Failure  to  accomplish  everything  has  sometimes  caused  abandon- 
ment of  measures  which  nevertheless  do  accomplish  much. 

"7.  Many  reasonable  and  promising  remedies  lack  the  endorsement  of 
accurate  experiment,  and  so  fail  to  command  the  confidence  of  the  practical 
farmer. 

"8.  The  disposition  to  speculate  on  the  weather  is  very  common.  A 
hope  that  heavy  rains  may  intervene  to  destroy  the  bugs  often  prevents 
action  which  it  is  thought  may  be  rendered  unnecessary  by  the  turn  of 
events." 

Much  of  this  applies  with  equal  force  in  our  own  State,  but  I  believe 
that  the  majority  of  our  progressive  farmers  will  chose  to  adopt  the  best 
measures  known  in  the  way  of  prevention  rather  than  run  the  risk  of 
another  Chinch  Bug  scourge  in  1888.  At  present  writing  Chinch  Biigs  are 
apparently  in  best  of  condition  for  wintering,  and  while  it  is  of  course 
possible  that  next  Spring  may  be  a  wet  one,  it  would  be  folly  to  depend 
upon  such  being  the  case.  The  question  then  arises,  what  can  be  done  to 
lessen  the  danger  the  coming  season?  I 'will  attempt  to  give  briefly,  and 
without  referring  here  to  supporting  evidence,  the  measures  which  I 
believe  should  be  adopted  in  every  neighborhood  where  the  Chinch  Bug  has 
tteen  present  during  the  past  season. 


THE  CHINCH  BUG  IN  IOWA.  11 

First. — As  soon  as  it  is  dry  enough  so  that  grass,  dry  leaves,  etc.,  will 
burn,  set  to  work  systematically  to  burn  over  every  foot  of  land  possible. 
Burn  all  old  corn  stalks,  and  grass  and  weeds  along  fences  and  in  corners. 
This  can  be  done  quite  safely  with  a  little  care  for  the  posts  where  the 
fence  is  of  wire;  for  board  fences  it  would  of  course  be  dangerous.  Carry 
the  fire  into  thickets  and  edges  of  timber,  burning  off  all  the  dead  leaves, 
and  attend  also  to  the  loose  bark  on  fallen  logs.  In  short,  carry  fire  into 
every  hiding  place  that  the  circumstances  will  permit.  It  should  be  done 
when  the  grass,  etc.,  is  dry  enough  to  burn  well  down  to  the  ground,  other- 
wise many  of  the  bugs  may  escape.  One  bug  killed  at  this  time  may  mean 
a  hundred  thousand  or  more  prevented  from  working  on  the  crops  in  Sum- 
mer; and,,  on  the  other  hand,  every  bug  escaping  may  mean  an  equal 
number  ready  to  devour  the  fruits  of  hard  labor.  While  it  will  pay  every 
farmer  to  adopt  this  method,  even  if  his  neighbors  do  not,  since  the  bugs 
for  the  most  part  do  not  travel  great  distances,  the  best  results  will  be 
reached  if  every  farm  in  the  neighborhood  is  thoroughly  renovated  by  fire. 
Second. — Make  a  careful  study  of  the  crops  to  be  planted  and  reduce  as 
much  as  possible  the  area  planted  to  wheat,  rye,  barley  and  Hungarian 
grass  especially,  and  to  a  less  extent  oats,  corn  and  meadow  grasses, 
remembering  that  bugs  feed  only  on  members  of  the  grass  family  of  plants, 
and  have  a  decided  preference  tor  wheat,  barley,  rye  and  Hungarian. 
Where  such  crops  cannot  be  suspended  plant  as  early  as  possible  and  sow 
heavily.  Defer  planting  corn  as  long  as  practicable  to  make  sure  that  none 
of  it  is  up  in  time  for  adults  wintering  over  to  be  attracted  to  it.  If 
possible  avoid  planting  it  next  to  wheat,  barley  or  Hungarian  grass,  and  if 
this  is  unavoidable  sow  strips  of  potatoes,  turnips,  buckwheat  or  some 
other  crop  not  relished  by  the  bugs  between  the  fields.  This  will  tend  to 
retard  migration  and  possibly  starve  some  of  the  younger  bugs,  while  if  the 
maturing  bugs  take  wing  and  scatter  generally  through  the  corn,  the  effect 
is  not  so  severe.  As  far  as  possible  plant  crops  not  affected  by  the  Chinch 
Bugs,  such  as  clover,  buckwheat,  flax,  beans,  potatoes,  turnips  and  other 
root  crops.  In  fields  intended  for  late  planting  of  corn  or  some  other  crop, 
an  early  planting  of  strips  of  wheat  or  Hungarian  to  attract  the  laying  of 
eggs,  to  be  plowed  under  as  soon  as  egg  laying  is  over,  will  result  in 
destruction  of  great  numbers  and  prevent  the  damage  they  might  have 
caused  in  other  fields.  Unless  the  strip  is  planted  to  some  crop  not  eaten 
by  the  bugs,  it  should  lie  two  or  three  weeks  at  least,  to  insure  the  death  of 
the  bugs  before  the  second  crop  is  planted,  though  when  plowed  under  deep 
there  is  little  probability  of  their  getting  again  to  the  surface. 

Third. — After  crops  are  started  keep  a  careful  watch  of  fields  in  wheat, 
barley,  etc.  If  portions  of  the  field  become  badly  infested  before  much 
growth  has  been  made,  while  other  parts  of  the  field  seem  free,  plow  under 
deep  and  later  plant  to  buckwheat,  turnips  or  some  crop  not  affected  by 
bugs.  If  the  whole  field  becomes  infested  early  it  may  pay  to  plow  under 
to  destroy  the  bugs  and  plant  as  late  as  possible  to  fodder  corn  or  other  late 
crop.  If  crop  is  far  enough  along  to  pay  for  cutting  as  hay,  or  ripe  enough 
for  early  cutting  for  the  grain,  clear  the  field  at  once;  burn  the  stubble  if 
dry  enough,  and  plow  under  as  quickly  as  possible.  The  bugs  make  very 
slow  progress  traveling  over  a  rough  plowed  field,  and  most  of  the  younger 
ones  at  least  must  perish. 

Fourth.— When  the  bugs  begin  to  migrate  into  corn  from  wheat  and 
other  fields,  or  rather  before  this  lias  commenced,  if  no  strips  of  crops 


12  IOWA  AGRICULTURAL  COLLEGE. 

disliked  are  between  the  fields,  see  to  it  that  a  strip  of  at  least  three  or  four 
yards  next  to  the  corn  is  plowed  and  finely  pulverized.  Then  as  soon  as 
bugs  begin  to  travel  mark  this  with  several  parallel  furrows  and  pulverize 
the  sides  of  these  furrows  thoroughly  by  dragging  a  heavy  block  or  log 
along  them.  The  bugs  cannot  crawl  up  the  sides  as  long  as  the  earth  rolls 
back  with  them,  and  vast  numbers  will  starve  to  death  along  such  an 
obstruction.  Spread  straw  along  side  of  these  furrows  toward  evening, 
and  the  bugs  will  go  under  it  for  the  night,  then  set  fire  to  it  in  the  morning 
before  the  bugs  start  to  travel  again.  Similar  precautions  can  be  used  in 
connection  with  strips  planted  to  potatoes,  etc.  At  this  time  too  the 
stubble,  if  it  has  not  been  plowed  under,  is  probably  dry  enough  to  burn,  if 
a  little  care  is  taken  to  carry  the  fire  over  thin  spots,  and  if  burned  in 
hottest  part  of  the  afternoon  hosts  of  bugs  will  be  burned.  While  the 
older  ones  have  already  left,  close  examination  will  probably  show  hosts  of 
small  ones  on  the  move.  If  the  bugs  reach  the  corn  and  begin  to  accumu- 
late there,  procure  a  few  gallons  of  cheap  kerosene  and  a  few  pounds  of 
cheap  bar  soap.  A  hand  force  pump  is  almost  essential,  though  the 
sprinkling  can  be  done  more  slowly  with  a  watering  pot.  The  best  nozzle  I 
know  of  for  the  purpose  is  the  cyclone  nozzle,  recommended  by  Professor 
Riley. 

Heat  a  quantity  of  water  (half  as  many  gallons  as  you  intend  to  use  of 
kerosene)  and  dissolve  in  it  half  a  pound  of  soap  to  each  gallon.  Add  this 
boiling  hot  to  the  kerosene  (one  gallon  of  suds  to  two  gallons  of  kerosene) 
and  churn  violently  together  from  ten  to  fifteen  minutes,  or  until  it  forms 
an  emulsion.  It  will  then  appear  thick  and  creamy,  and  will  not  separate 
on  standing  or  cooling.  The  churning  is  best  done  by  forcing  the  fluid 
through  the  force  pump,  driving  it  through  a  short  hose  without  the  spray 
nozzle  back  into  the  vessel  from  which  it  is  drawn.  Having  prepared  this 
emulsion  it  may  be  mixed  at  pleasure  with  pure  water,  or  water  with  a 
little  soap  in  it,  using  nine  gallons  of  water  to  one  gallon  of  the  emulsion. 
This  gives  thirty  gallons  of  mixture  for  every  two  gallons  of  kerosene.  It 
may  be  diluted  still  further  if  desired,  but  should  not  at  the  farthest  be 
diluted  so  as  to  use  more  than  fourteen  or  fifteen  gallons  of  water  to  each 
gallon  of  emulsion.  The  mixture  in  barrels  may  be  drawn  in  a  wagon 
along  side  the  rows  of  corn,  and  the  bugs  sprayed  by  directing  the  nozzle 
upon  the  stalks  where  they  are  massed.  To  reach  rows  beyond  the  first 
two-or  three  it  will  be  necessary  to  have  a  long  hose  and  one  man  to  manip- 
ulate the  nozzle,  passing  among  the  hills  for  as  many  rows  as  convenient, 
while  another  works  the  force  pump  and  manages  the  team.  This  method 
is  applicable  where  the  bugs  are  massed  on  a  few  rows  of  corn  next  to 
wheat  and  may  prevent  serious  damage  to  the  bulk  of  the  field, 

Fifth.— When  corn  fields  are  infested  throughout  and  liable  to  be 
seriously  damaged,  a  plan  already  very  generally  adopted  is  to  cut  it  up  for 
fodder. 

Sixth.— And  lastly,  after  the  season's  crops  are  attended  to,  every  effort 
should  be  made  to  reduce  the  number  for  the  next  year.  The  rubbish  in 
fence  corners,  the  dry  grass,  leaves,  etc.,  may  be  raked  into  heaps  from 
places  not  accessible  to  fire.  These  will  form  excellent  attraction  for  the 
bugs  when  secreting  themselves  for  their  Winter  hibernation,  and  then  on 
some  dry  day  in  late  Eall  or  early  Winter,  or  in  early  Spring,  the  whole 
mass  may  be  burned.  At  the  same  time,  all  ground  covered  with  grass, 
leaves,  etc.,  should  be  burned  over  as  thoroughly  as  possible.  There  is  an 


THE  CHINCH  BUG  IN  IOWA. 


13 


advantage  in  doing  this  late  in  Fall ,  after  bugs  have  taken  up  their  Winter 
quarters,  in  that  there  is  more  probability  of  burning  thoroughly  to  the 
ground,  and  bugs,  if  any  escape,  will  have  difficulty  in  finding  shelter  for 
the  Winter,  and  many  are  likely  to  perish  by  the  attacks  of  birds  or  other 
natural  enemies. 

Many  of  the  measures  recommended  for  the  latter  part  of  the  season 
may  be  unnecessary,  and  of  course  the  greatest  gain  results  if  careful 
attention  is  given  to  the  matter  at  the  beginning  of  the  season.  As  far  as 
possible  there  should  be  concerted  action  by  all  the  farmers  in  a  neighbor- 
hood, for  though  it  may  pay  the  individual  farmer  to  do  all  he  can  for  the 
protection  of  his  own  crops,  he  can  but  partially  succeed  it  bugs  are 
continually  coming  in  from  the  neglected  fields  of  his  neighbor.  Each  man 
should  study  the  conditions  on  his  own  farm,  become  thoroughly  familiar 
with  the  habits  of  the  bug,  the  crops  it  will  infest  and  the  time  and  manner 
of  its  work,  and  then  adapt  his  crops  and  the  remedies  he  applies  to  the 
particular  conditions  of  his  locality. 


Maker 
Syracuse, 
PH.JW-N 


±5vat 


491508 


C.b-07 


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